Portable, refrigerant recovery unit with a condenser bypass mode

ABSTRACT

A portable, refrigerant recovery unit to transfer refrigerant from a refrigerant system to a storage tank. The recovery unit includes a condenser bypass mode controlled by a valving arrangement that can be employed when the cooling and phase change functions of the condenser are not needed such as commonly exist during the initial stages of the overall recovery process when the refrigerant from the system may already be in liquid phase. In such cases, the bypass mode avoids having the flow run through the tubing and other plumbing of the condenser which otherwise would add significant length (e.g., 2-3 feet or more) and resistance to the flow through the recovery unit for a faster overall recovery process. The valving arrangement of the recovery unit has a single control knob and can be positioned in a plurality of modes including off, condenser bypass, recovery, and condenser purge.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/938,570 filed Feb. 11, 2014, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the field of portable, refrigerant recovery units.

2. Discussion of the Background

Portable, refrigerant recovery units are primarily used to transfer refrigerant from a refrigerant system to a storage tank. In this manner, the refrigerant can be removed from the system and captured in the tank without undesirably escaping into the atmosphere. Needed repairs or other services can then be performed on the system.

Efficiency and speed of operation of the recovery process are critical factors as the faster the refrigerant can be recovered, the faster the repairs or other services can be made to the system and the faster it can be put back on line. Significant productive and financial losses can then be minimized by putting the refrigerant system back in use as quickly as possible be it to prevent food spoilage in a grocery store setting or the shutdown of a hospital or office building due to the lack of air conditioning. Savings can also be realized in the efficient use of the time of the personnel servicing the system.

With this and other goads in mind, the present invention was developed. In it, a portable, refrigerant recovery unit is provided which includes a mode of operation controlled by a multiple valve manifold or valving arrangement that bypasses the condenser in the recovery unit when the condenser is not needed to perform its cooling and phase change functions. Such conditions can commonly exist when the recovery process is first initiated and the recovery unit is already pumping liquefied refrigerant from the system to the storage tank. The valving arrangement of the recovery unit has a single control knob for ease of operation and can be positioned in a plurality of modes including off, condenser bypass, recovery, and condenser purge.

SUMMARY OF THE INVENTION

This invention involves a portable, refrigerant recovery unit that efficiently and effectively operates to transfer refrigerant from a refrigerant system to a storage tank as quickly as possible. The recovery unit includes a condenser bypass mode controlled by a multiple valve manifold or valving arrangement that can be employed when the cooling and phase change functions of the condenser are not needed. Such conditions can commonly exist during the initial stages of the overall recovery process when the refrigerant from the system may already be in liquid phase. In such cases, the bypass mode avoids having the flow run through the tubing and other plumbing of the condenser which otherwise would add significant length (e.g., 2-3 feet or more) and resistance to the flow through the recovery unit. The result is a significant reduction in the time needed to perform the overall recovery operation (e.g., 30 minutes versus 1.5 hours or more) and the accompanying savings in time and cost to perform the repairs on the system and get it back on line.

The valving arrangement of the recovery unit has a single control knob and can be positioned in a plurality of modes including off, condenser bypass, recovery, and condenser purge. The condenser bypass mode is typically operated first after which the recovery unit is switched to the recovery mode to complete the transfer of the remaining refrigerant (which is typically mostly vapor) from the refrigerant system to the storage tank. In this recovery mode, the refrigerant does pass through the condenser of the recovery unit to be cooled and condensed. A purge mode is also provided in which the condenser can subsequently be cleared of any residual refrigerant and the residual refrigerant safely confined to the storage tank. The overall result of having the bypass mode and the valving arrangement is a significant increase in the efficiency and speed (e.g., 2-3 times or more faster) of the overall recovery process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of the portable, refrigerant recovery unit of the present invention.

FIG. 2 shows the recovery unit in a typical operating arrangement to transfer refrigerant from a refrigerant system to a storage tank.

FIGS. 3 a-3 c illustrate the operation of the recovery unit in a recovery mode to transfer refrigerant from the refrigerant system to the storage tank of FIG. 2.

FIGS. 4 a-4 d illustrate details of the multiple valve manifold or valving arrangement of the recovery unit as positioned to recover the refrigerant.

FIGS. 5 a-5 c illustrate the recovery unit in its off position.

FIGS. 6 a-6 c illustrate details of the valving arrangement of the recovery unit in its off position.

FIGS. 7 a-7 c illustrate the operation of the recovery unit in a bypass mode that transfers refrigerant from the refrigerant system to the storage tank of FIG. 2 without going through the condenser of the recovery unit.

FIGS. 8 a-8 c illustrate details of the valving arrangement of the recovery unit as positioned in the bypass mode of operation.

FIGS. 9 a-9 c illustrate the operation of the recovery unit in a purge mode to clear the condenser of any residual refrigerant and transfer it safely to the storage tank of FIG. 2.

FIGS. 10 a-10 c illustrate details of the valving arrangement of the recovery unit as positioned in the purge mode.

FIG. 11 is a view similar to FIG. 2 but with the recovery unit in a push/pull configuration with the refrigerant system and the storage tank.

FIGS. 12 a and 12 b are schematic showings of other designs of the valving arrangement controlling the flow paths through the recovery unit.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a front elevational view of the portable, refrigerant recovery unit 1 of the present invention. FIG. 2 illustrates the recovery unit 1 of the present invention in a typical operating arrangement to transfer refrigerant from the refrigerant system 2 to the storage tank 4. In this arrangement, refrigerant from the system 2 is being delivered through the line 6 to the inlet line 3 of the recovery unit 1. From the inlet line 3 as shown in FIGS. 3 a-3 c, the refrigerant flows in series within the recovery unit 1 in a first direction to and through the compressor 5 and to and through the condenser 7 to the outlet line 9 of the recovery unit 1. The outlet line 9 in turn is in fluid communication with the line 10 of FIG. 2 leading to the storage tank 4.

In this operating recovery mode, the refrigerant passes through the multiple valve manifold or valving arrangement 11 of FIGS. 4 a-4 c. More specifically and with the control knob 13 on the front panel of the recovery unit 1 of FIG. 2 in the position of FIG. 2 and FIGS. 4 a and 4 b, the refrigerant passes as in FIGS. 3 a-3 c from the inlet line 3 through the valve 15 (see FIG. 3 a and also FIGS. 4 b and 4 c) to and through the compressor 5 and through the valve 17 to the condenser 7. From the condenser 7, the refrigerant subsequently flows through valve 19 to the outlet line 9 of the recovery unit 1 and on to the line 10 of FIG. 2 leading to the storage tank 4.

As explained in more detail below, the valves 15, 17, 19, and 21 of the valving arrangement 11 can be selectively positioned to place the recovery unit 1 in four modes. In the mode of FIGS. 5 a-5 c and 6 a-6 c, the recovery unit 1 is closed off (see FIG. 5 a) from allowing any refrigerant to flow through it between the inlet line 3 and the outlet line 9. The valve 15 in this off position (FIG. 5 a) is then positioned by the gearing arrangement 23, 25, 27, and 29 (FIG. 6 b) to prevent or block any incoming refrigerant from passing from the inlet line 3 through the valve 15 into the recovery unit 1.

Rotation of the single control knob 13 in FIG. 5 b 180 degrees from the off position to the position of FIG. 3 b will then place the recovery unit 1 in the previously discussed recovery mode of FIG. 3 a-3 c and 4 a-4 c. In doing so, the valves 15, 17, 19, and 21 of the valving arrangement 11 are rotated 180 degrees about their respective rotational axes 15′, 17′, 19′, and 21′ (see FIG. 4 c) which are horizontal and parallel to each other in the orientation shown in FIGS. 4 a-4 c. The rotation of each valve by the respective rotating gear can be accomplished in any number of manners. In one illustrated manner, a simple arrangement of a protruding flange or key 31 is provided as shown in FIG. 4 d on the back of each gear that is received in a groove 33 in the respective valve (see FIG. 5 a).

In conventional recovery units with condensers, the normal operation is from the off position discussed above directly to the recovery position also discussed above. However, in the present invention and between the off and recovery positions of the control knob 13 of FIGS. 2 is a novel condenser bypass position. In this position as shown in FIGS. 7 a-7 c, the flow path through the recovery unit 1 of the present invention bypasses the condenser 7. In this manner, the refrigerant then flows directly from the inlet line 3 to and through the compressor 5 to the outlet line 9 and avoids the condenser 7 altogether (see also FIGS. 8 a-8 c).

That is and in contrast to other recovery units that always have their flow pass through the condenser even under conditions when the cooling and phase change functions of the condenser are not needed (e.g., pumping only liquid refrigerant or small amounts of vapor and in push/pull configurations), the present recovery unit 1 allows the flow in such circumstances to run directly from the inlet line 3 (see FIG. 7 a) to the compressor 5 to the outlet line 9. In this manner and under such circumstances that can commonly exist during the initial stages of an overall recovery process, the bypass mode avoids having the flow run through the tubing and other plumbing of the condenser which otherwise would add significant length (e.g., 2-3 feet or more) and resistance to the flow through the recovery unit 1. Once this bypass mode is completed, the recovery unit 1 can then be switched to the recovery mode of FIGS. 3 a-3 c and 4 a-4 c to complete the transfer of the remaining refrigerant (which is typically mostly vapor) from the refrigerant system 2 of FIG. 2 to the storage tank 4. In this recovery mode, the refrigerant does pass through the condenser 7 of the recovery unit 1 to be cooled and condensed. The overall result of having the bypass mode prior to the recovery mode is a significant increase in the efficiency and speed (e.g., 2-3 times or more faster) of the overall recovery process (e.g., moving 8-12 gallons/minute versus 4 gallons/minute).

Completing the description of the operating modes of the recovery unit 1 of the present invention and after the recovery mode of FIGS. 3 a-3 c and 4 a-4 c is finished, the control knob 13 can be additionally rotated to the purge position illustrated in FIGS. 9 a-9 c and 10 a-10 c. In this purge position, the condenser 7 can then be cleared of any residual refrigerant and the residual refrigerant safely confined to the storage tank 4. In doing so, the flow path through the condenser 7 is in a direction opposite to the flow path of the recovery mode of FIG. 3 a through the condenser 7. However, the direction of the flow through the compressor 5 in the purge mode is still in the same direction as in the recovery mode.

Although described above in a different order of operation for clarity, the normal sequence of operation of the recovery unit 1 is from being off (FIG. 6 a) to condenser bypass (FIG. 7 a) to recovery (FIG. 3 a) to purge (FIG. 9 a) and back to off (FIG. 4 a). Nevertheless, the recovery unit 1 can be operated in difference sequences if desired or beneficial (e.g., if one mode is interrupted before completion and it is desirable that it be resumed out of the normal order).

Referring again to the recovery and bypass operational modes of FIGS. 3 a and 7 a, the flows in these two modes pass through the common, three-ported ball valve 17 (see also FIGS. 4 c and 8 c). More specifically and in the recovery mode of FIGS. 3 a and 4 c, the refrigerant flows through the recovery unit 1 along a first path from the inlet line 3 to and through the compressor 5 and to and through the condenser 7 to the outlet line 9. In doing so, the flow of this first path runs through the valve 17 with the valve 17 (see FIG. 4 c) selectively positioned so the flow enters the inlet port 41 of the valve 17 and exits through the outlet port 41′. In contrast and in the bypass mode of FIGS. 7 a and 8 c, the refrigerant flows through the recovery unit 1 along a second path from the inlet line 3 to and through the compressor 5 to the outlet line 9 and avoiding the condenser 7. In doing so, the flow of this second path runs through the valve 17 with this common valve 17 (see FIG. 8 c) selectively positioned so the flow enters the inlet port 41 of the valve 17 and exits through the second outlet port 41″. The passages in the common valve 17 (FIG. 8 c) then form a T-shape with the inlet port 41 at the bottom or stem of the T and the outlet ports 41′ and 41″ respectively at the ends of the arms of the T. The two outlet ports 41′ and 41″ are in fluid communication with the inlet port 41 and each other. in operation, one of outlet ports 41′ and 41″ is then selectively blocked off within its bearing depending upon the rotational positioning of the common valve 17 in FIGS. 4 c and 8 c. The use of the common valve 17 to selectively accommodate the first and second flow paths of the recovery and bypass modes adds to the simplicity of the design and operation of the multiple valve manifold 11.

Further adding to this simplicity is the use of a second common valve at 15 upstream of the compressor 5 in FIGS. 4 c and 8 c. This second common valve 15 also selectively accommodates the first and second flow paths of the recovery and bypass modes. The second common valve 15 is similarly a three-ported ball valve with an outlet port 43 and two inlet ports 43′ and 43″. This is in contrast to the common valve 17 that has a single inlet port and two outlet ports. In operation, the flow of the first path in the recovery mode runs through the valve 15 with the valve 15 (see FIG. 4 c) selectively positioned so the flow enters the inlet port 43′ of the valve 15 and exits through the outlet port 43. In the bypass mode of FIGS. 7 a and 8 c, the refrigerant then flows through the recovery unit 1 along the second path from the inlet line 3 to and through the compressor 5 to the outlet line 9 and avoiding the condenser 7. In doing so, the flow of this second path runs through the valve 15 with the common valve 15 (see FIG. 8 c) selectively positioned so the flow enters the second inlet port 43″ of the valve 15 and exits through the outlet port 43. As shown, the intersecting passages in the common valve 15 can be orthogonal to each other with the two inlet ports 43′ and 43″ in fluid communication with the outlet port 43 and each other. In operation, one of inlet ports 43′ and 43″ is then selectively blocked off within its bearing depending upon the rotational positioning of the common valve 15 in FIGS. 4 c and 8 c.

The common valve 17 offers the further advantage in the purge mode of FIGS. 9 a and 10 c by selectively accommodating a third flow path in which the condenser 7 can be cleared of any residual refrigerant and the residual refrigerant safely confined to the storage tank 4 of FIG. 2. In this purge mode, the valve 15 upstream of the inlet line 3 in FIGS. 9 a and 10 c is closed to the inlet line 3. The flow through the condenser 7 is then reversed to pass from the closed valve 19 to and through the condenser 7 and to and through the compressor 5 to the outlet line 9. In doing so, the flow of this third path runs through the valve 17 with the common valve 17 (see FIG. 10 c) selectively positioned so the flow enters the inlet port 41 of the valve 17 and exits through the first outlet port 41′.

It is noted that in a push/pull operating configuration of the recovery unit 1 as in FIG. 11 with the connections of the inlet and outlet lines reversed (i.e., the inlet line 3 selectively connected in fluid communication with the vapor port 12 of the storage tank 4 via line 14 and the outlet line 9 selectively connected in fluid communication with the system 2 via line 16), the flow path through the recovery unit 1 would be set as in the bypass mode of FIGS. 7 a-7 c and 8 a-8 c. The flow would then be from the vapor port 12 of the storage tank 4 to the inlet line 3 to and through the compressor 5 to the outlet line 9 and on to the system 2 with the additional line 18 of FIG. 11 connected between the system 2 and the liquid port 20 of the storage tank 4. In this manner, the recovery unit 1 is used to create a siphon to blow or push the refrigerant out of the system 2 while simultaneously pulling or sucking the refrigerant into the storage tank 4. Such push/pull configurations are useful for initially recovering large amounts of liquid refrigerant from the system 2. However, unlike other recovery units with condensers, the vapor from the storage tank 4 does not pass through the condenser 7 of the recovery unit 1 of the present invention where it would be undesirably cooled or condensed to a liquid in the push/pull configuration of FIG. 11. Rather, it stays as a vapor at relatively high pressure as it further acquires latent heat from the compressor 5 as it runs through it and is compressed. The flow through the recovery unit 1 in such an alignment then runs directly from the inlet line 3 (see FIG. 7 a) to the compressor 5 to the outlet line 9. As in the previously discussed bypass mode, the flow path of the push/pull configuration additionally avoids having the vapor from the storage tank 4 run through the tubing and other plumbing of the condenser which otherwise would add significant length (e.g., 2-3 feet or more) and resistance to the flow through the recovery unit 1. In this manner, the overall result of having these bypass modes is a significant increase in the efficiency and speed of the overall recovery process when a push/pull mode is used in addition to the modes of FIGS. 1-10 c.

FIGS. 12 a and 12 b schematically show other designs of the valving arrangement controlling the flow paths through the recovery unit. In the embodiment of FIG. 12 a, the same functions as in FIGS. 1-11 are performed but using only three valves (i.e., a two-way valve at 51, a three-way valve at 53, and a four-way valve at 55). The embodiment of FIG. 12 b is even further simplified by using only two valves (i.e., the two-way valve at 57 and a six-ported ball valve at 59) to perform the same functions as in FIGS. 1-11.

It is specifically noted that the condenser 7 of the present invention in all of the illustrated embodiments could be made as a physically integral part with the other parts (e.g., compressor 5) of the recovery unit 1. The parts would then essentially be fixed relative to each other within a common casing. However, the condenser 7 could also be a separable part of the recovery unit 1 if desired so that it could, for example, be physically separated from the other parts and submerged in ice water or other exterior cooing media. Although separable, the flow paths to and from the condenser 7 and through the recovery unit 1 and its other parts would still be as illustrated in the various modes discussed above.

The above disclosure sets forth a number of embodiments of the present invention described in detail with respect to the accompanying drawings. Those skilled in this art will appreciate that various changes, modifications, other structural arrangements, and other embodiments could be practiced under the teachings of the present invention without departing from the scope of this invention as set forth in the following claims. In particular, it is noted that the word substantially is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement or other representation. This term is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter involved. 

We claim:
 1. A portable, refrigerant recovery unit for transferring refrigerant from a refrigerant system to a storage tank, said recovery unit having an inlet line selectively connectable in fluid communication to said system and an outlet line selectively connectable in fluid communication to said storage tank, said recovery unit further including at least a compressor and a condenser and a valving arrangement to selectively establish at least first and second flow paths through the recovery unit from the inlet line thereof to the outlet line thereof with (a) said first flow path running from said inlet line to and through the compressor and to and through the condenser to said outlet line and (b) said second flow path bypassing said condenser and running from said inlet line to and through the compressor to said outlet line without running through the condenser.
 2. The recovery unit of claim 1 wherein said first flow path runs in series from the inlet line to and through the compressor and the condenser in a first direction to said outlet line.
 3. The recovery unit of claim 2 wherein said valving arrangement further selectively establishes a third flow path blocked from fluid communication with the inlet line and running within said recovery unit to and through the condenser in a second direction opposite to said first direction and to and through the compressor in said first direction to the outlet line to purge the condenser.
 4. The recovery unit of claim 3 wherein said valving arrangement further selectively establishes an off position blocking flow between the inlet line and outlet line of the recovery unit.
 5. The recovery unit of claim 1 wherein said first and second flow paths selectively run through at least one common valve having at least one inlet port and two outlet ports, said common valve being selectively positionable between at least first and second positions with (a) the first position forming a portion of the first flow path and placing the inlet port in fluid communication with the outlet line of the recovery unit through one of the outlet ports of the common valve and (b) the second position forming a portion of the second flow path and placing the inlet port in fluid communication with the outlet line of the recovery unit through the second of the outlet ports of the common valve.
 6. The recovery unit of claim 5 wherein the two outlet ports of the common valve are in fluid communication with the inlet port and each other.
 7. The recovery unit of claim 5 wherein said common valve is a ball valve having passages therethrough forming a T-shape having a stem and two arms with the inlet port at the stem of the T-shape and the outlet ports at the respective ends of the arms of the T-shape.
 8. The recovery unit of claim 5 wherein said first and second flow paths selectively run through at least a second common valve having at least two inlet ports and one outlet port, said second common valve being positioned upstream of the compressor in both said first and second flow paths and being selectively positionable between at least first and second positions with (a) the first position forming a portion of the first flow path and placing one of the inlet ports in fluid communication with the outlet line of the recovery unit through the outlet port of the second common valve and (b) the second position forming a portion of the second flow path and placing the second of the inlet ports in fluid communication with the outlet line of the recovery unit through the outlet port of the second common valve.
 9. The recovery unit of claim 8 wherein the two inlet ports of the second common valve are in fluid communication with the outlet port and each other.
 10. The recovery unit of claim 8 wherein said second common valve is a ball valve having passages therethrough intersecting orthogonally and respectively forming the two inlet ports and one outlet port.
 11. The recovery unit of claim 8 wherein said second common valve is upstream of the first mentioned common valve in both said first and second flow paths and said first and second flow paths each run through the second common valve and the first mentioned common valve in the same direction.
 12. The recovery unit of claim 1 wherein the first and second flow paths respectively run through the compressor in the same direction.
 13. A portable, refrigerant recovery unit for selectively transferring refrigerant from a refrigerant system to a storage tank in a recovery mode and a push/pull mode, said recovery unit having an inlet line and an outlet line, said storage tank having a vapor port and a liquid port with said inlet line being selectively connectable in fluid communication to said system and said outlet line being selectively connectable in fluid communication to the liquid port of said storage tank in said recovery mode and said inlet line being selectively connectable in fluid communication to the vapor port of said storage tank and said outlet line being selectively connectable in fluid communication to said system in said push/pull mode, said recovery unit further including at least a compressor and a condenser and a valving arrangement to selectively establish (i) at least a first flow path through the recovery unit from the inlet line thereof to the outlet line thereof in said recovery mode and (ii) a second flow path through the recovery unit from the inlet line thereof to the outlet line thereof in said push/pull mode with (a) said first flow path running from said inlet line to and through the compressor and to and through the condenser to said outlet line and (b) said second flow path bypassing said condenser and running from said inlet line to and through the compressor to said outlet line without running through the condenser.
 14. The recovery unit of claim 13 wherein said first flow path runs in series from the inlet line to and through the compressor and the condenser in a first direction to said outlet line.
 15. The recovery unit of claim 13 wherein the first and second flow paths respectively run in the same direction through the compressor.
 16. The recovery unit of claim 13 wherein said valving arrangement further selectively establishes an off position blocking flow between the inlet line and outlet line of the recovery unit in said recovery and push/pull modes.
 17. The recovery unit of claim 13 wherein said first and second flow paths selectively run through at least one common valve having at least one inlet port and two outlet ports, said common valve being selectively positionable between at least first and second positions with (a) the first position forming a portion of the first flow path and placing the inlet port in fluid communication with the outlet line of the recovery unit through one of the outlet ports of the common valve and (b) the second position forming a portion of the second flow path and placing the inlet port in fluid communication with the outlet line of the recovery unit through the second of the outlet ports of the common valve.
 18. The recovery unit of claim 17 wherein said first and second flow paths selectively run through at least a second common valve having at least two inlet ports and one outlet port, said second common valve being positioned upstream of the compressor in both said first and second flow paths and being selectively positionable between at least first and second positions with (a) the first position forming a portion of the first flow path and placing one of the inlet ports in fluid communication with the outlet line of the recover/unit through the outlet port of the second common valve and (b) the second position forming a portion of the second flow path and placing the second of the inlet ports in fluid communication with the outlet line of the recovery unit through the outlet port of the second common valve
 19. The recovery unit of claim 17 wherein said second common valve is upstream of the first mentioned common valve in both the first and second flow paths and said first and second flow paths each run through the second common valve and the first mentioned common valve in the same direction 